Pachypsylla
Pachypsylla is a genus of psyllids. Each of its four species lay eggs on the leaves of the Celtis occidentalis tree. Upon hatching, the young psyllids become encased in a "gall" which the young leaf parts grow in response to the infestation. Species of Pachypsylla include Pachypsylla celtidisgemma, Pachypsylla celtidismamma, Pachypsylla celtidisvesiculum and Pachypsylla venusta.
, nymph
on hackberry
